Musk has been sleeping at the Tesla factory and staying up late building subs for cave rescues. It's not a good recipe for smart use of Twitter.

Tweeting tired is not a good idea. It's not as bad as driving drunk, but it could have similar impact on your career.

Ask Elon Musk.

The car-building solar-power-generating space-conquering genius has feet of clay just like the rest of us, as a recent episode of since-deleted tweets reveal.

Musk and his engineers built a tiny unpowered sub that could have been used to help rescue the Thai soccer team that was stranded in a cave. But British cave diver Vern Unsworth, who helped Thai authorities with the search and rescue operation, called it a PR stunt.